High brake temperatures can lead to brake fade, which can cause catastrophic brake failure. Brake failure is a serious traffic hazard, especially in heavy transport vehicles, such as buses, trucks and tractor-trailers. For example, a loss of braking capability on the highways or roadways could lead to serious accidents and fatalities. Consequently, the Department of Transportation in many states perform spot checks of heavy vehicles such as trucks on their highways.
Typically, checking brakes on a highway involves stopping the truck and dismantling and examining the brakes. However, this process is very expensive and time consuming. The labor involved can be costly, as well as the loss of truck and driver time involved in pulling over the trucks, queuing them up, inspecting them and completing the associated paperwork.